Gas blast circuit breaker having series-connected movable nozzle contacts



June 30, 1970 AUMAYER ETAL 3,518,388

GAS BLAST CIRCUIT BREAKER HAVING SERIES-CONNECTED MOVABLE NOZZLE CONTACTS I Filed Nov. 2, 1967 3 Sheets-Sheet 1 arm uz/vwzzv Y me/ 72 {arm-4 e/n/e H. AUMAYER ET AL 3,518,388

June 30, 1970 GAS BLAST CIRCUIT BREAKER HAVING SERIES-CONNECTED MOVABLE NOZZLE CONTACTS 3 Sheets-Sheet :3

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GAS BLAST CIRCUIT BREAKER HAVING SERIES-CONNECTED MOVABLE NOZZLE CONTACTS Filed Nov. 2. 1967 3 Sheets-Sheet 5 f 'z- Es'= E.

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T? TY 4:72 ewz, 6955,0 654;; Jan JTWZA/[Yf United States Patent 3,518,388 GAS BLAST CIRCUIT BREAKER HAVING SERIES- CONNECTED MOVABLE NOZZLE CONTACTS Hansruedi Aumayer, Los Angeles, Calif., Otto Jensen, Malvern, Pa., and Fritz Kesselring, Kusnacht, Zurich, Switzerland, assignors of one-half each to I-T-E Imperial Corporation, Philadelphia, Pa., a corporation of Delaware, and Siemens Aktiengesellschaft, Berlin and Munich, Germany, a corporation of Germany Filed Nov. 2, 1967, Ser. No. 680,200 Claims priority, application Germany, Nov. 9, 1966,

US. Cl. 200148 4 Claims ABSTRACT OF THE DISCLOSURE A high voltage gas blast circuit breaker having an angularly rotatable contact arm having two nozzles at either end. The movable contact arm angularly moves within a high-pressure gas container, with the nozzle contacts at the end of the arm engaging and disengaging a stationary contact. Gas flows into the nozzles to a gas discharge region to extinguish arcs drawn when the contact arms are rotated to a disengaged position. The two nozzles and contact arm may be a hollow, continuous, generally cylindrical rotating arm which communicates with a gas discharge region.

This invention relates to high voltage gas blast breakers, and more particularly relates to a contact structure for gas blast circuit breakers in which the opposite ends of a rotatable contact arm carry or cooperate with gas discharge nozzles through which gas will flow to extinguish arcs when the nozzles are opened by rotation of the stationary contacts away from their cooperating stationary contacts.

It is a primary object of this invention to provide a gas blast circuit breaker having improved interrupting capacity.

Another object of this invention is to provide a novel gas blast circuit breaker having a simplified mechanical arrangement wherein the movable contact contains two movable nozzles through which high pressure gas may pass to extinguish the are drawn between the nozzles and cooperating stationary contacts.

A further object of this invention is to provide a novel, movable bridging contact for gas blast circuit breakers which has a hollow tubular form containing two discharge orifices at either end which serves as movable contacts, with gas flowing into each of these nozzles and into a common discharge orifice when the cylindrical hollow tube is rotated to move the nozzles away from cooperating stationary contacts which are series-connected through the movable contact.

These and other objects of this invention will become apparent from the following description when taken in connection with the drawings in which:

FIG. 1 is a schematic partially cross-sectioned illustration of a circuit breaker constructed in accordance with the present invention.

FIG. la is an enlarged cross-sectional diagram of the rotatable contact of FIG. 1.

FIG. lb is a cross-sectional view of FIG. 1a taken across the section line 1b-1b in FIG. In.

FIG. is a detailed across-sectional view of the operating piston and closing control valve of FIG. 1.

FIG. 2 is a schematic partially cross-sectional illustration of a second embodiment of the invention wherein the hollow tubular rotatable contact is replaced by two counter-rotating contact arms which carry nozzles at their 3,518,388 Patented June 30, 1970 "ice opposite ends which cooperate with conductive conduit outlets.

Referring first to FIGS. 1, la, lb and 1c, there is illustrated a high pressure tank 1 (schematically shown in dotted lines in FIG. lb) which has a suitable sealed cover 2. Lead-through insulator bushings 3 and 4, which support terminal conductors 5 and 6, respectively, carry stationary contacts 7 and 8, respectively, at their inner ends. A rotatable tubular contact bridge 9 is then provided which is a hollow shaft which communicates with and rotates with respect to support shaft 10, with communication between shaft 10 and tube 9 provided as by openings 10a and 10b in shaft 10. Tubular bridge 9 is then provided with nozzle-shaped ends 11 and 12, respectively, which cooperate with stationary contacts 7 and 8, respectively. Shaft 10 is then rotatably mounted on conduit 13 in any desired manner as by the provision of a suitable rotation seal 13a, shown in FIG. 1b.

Channel 13 then communicates with volume 14 contained within sealed cylinder 14a, which supports tank 1 as by the connection 15 to the rear side of tank 14a, shown in FIG. 1. The tank 14a defines a cylinder which carries piston 17 which is secured to a piston rod 18 which has an upper slotted end 18a (FIG. 1c), which is connected to a suitable pin extending from bell crank lever 19. Bell crank lever 19 is then pivotally supported by yoke 20, extending from the top of cylinder 14a. The upper end of bell crank lever 19 is then pivotally connected to a link 21, which is, in turn, pivotally connected to pivot point 21a (FIG. 1a) of the rotatable contact bridge 19. A valve disk 22, which is slidable on piston rod 18 and sealed thereto, as illustrated in FIG. 10, by seal 22a, is then movable into sealing engagement with the valve seat 22b .(FIG. 10) in the top of cylinder 14a. Two outlet valves 23 and 24 are then provided where outlet valve 23 is contained in a plate atop support cylinder 25 and controls the connection of low-pressure volnine 37, which is the interior of insulator 25, to the interior volume 14 within cylinder 14a. The construction of valve 24 will be later described as shown in detail in FIG. 16.

Valve 23 is actuated by electrodynamic drive structure 26 which consists of a fixed winding 27 and a movable metallic disk 28. Disk 28 is connected to an insulation rod 29 which is connected to the bottom of valve disk 23. The support insulator 25 is then carried on the circuit breaker base 30 which contains leads 31 and 32 which extend through suitable insulators and are connected to coil 27. The leads 31 and 32 are then energized by some suitable control circuit which is external of base 30. Base 30 further contains a compressor 33 which has an input conduit 33a. Compressor 3 collects the low pressure gas within volume 37 and compresses this gas .to a high-pressure which is connected to conduit 34. Conduit 34 extends into volume 14 which receives opening 15 of conduit 13. Therefore, the tubular bridge 9having ends 11 and 12 (which are not sealed to contact 7 and 8) and volume 14 are normally at the high-pressure normally contained within interrupter chamber 1.

The operation of the breaker from the closed position of FIG. 1 is as follows:

A current pulse is applied to the leads extending through lead-ins 31 and 32 to the coil 27 Strong electrodynamic repelling forces are then established between coil 27 and disk 28 so that operating rod 29 is moved upwardly very rapidly. This opens valve disk 23 to evacuate the high-pressure gas beneath piston 17 and establishes an open path for the flow of high pressure gas from chamber 1 through the nozzles 11 and 12 and through volume 14 into low-pressure region 37. At the same time, piston 17 moves downwardly to turn bell crank lever 19 in a clockwise direction. It is to be noted that the bell crank 19 and link 21 form an overcenter toggle with the pivot between link 21 and bell crank 19 to the left of the pivotal connections to yoke 20, contact 9, thereby preventing accidental opening of contact 9. The clockwise rotation of yoke 19 breaks the toggle, and the tubular contact bridge 9 rotates counterclockwise, thereby drawing arcs from contact 7 to nozzle 11 and from contact 8 to nozzle 12. At the same time, high-pressure gas, which may be sulfur hexafluoride or air, or the like, flows into nozzles 11 and 12, through channel 13, and finally into low pressure region 37. The flow of the gas into nozzles 11 and 12 acts to extinguish the arcs drawn thereto with current flow extinguished at the next current zero.

Shortly before piston 17 reaches the dotted line position 17a, shown in FIG. 1, valve plate 22 is engaged by member 35 on shaft 18 and is moved into valve seat 2212 to shut off communication between the pressure in tank 1 and the top of piston 17. Thus, the piston 17 is held in its downard position, holding the contacts open by the high-pressure which is now trapped above piston 17. At the same time, valve plate 23 drops back to the closed position, with shaft 29 falling. back to the position shown in FIG. 1 after the end of the pulse applied to coil 27. Normally, this could be accomplished by gravity or by other auxiliary means, such as suitable spring biases, or the like, which are not shown. This then closes off channel 13 and port 15 to stop the flow of air from container 1 and into orifices 11 and 12.

When piston 17 is in the position 1711, there exists high pressure above as well as below the piston 17a, since the valve 22 closes only at the last moment. Note that a small bleed channel (not shown) can connect the interior of tank 1 and the Volume on top of piston 17 to keep high pressure on top of piston 17 when the breaker is open. Referring to FIG. 10 and if the circuit is to be closed, an impulse is applied to insulating rod 24b in the direction of the arrow. The valve head 24a is lifted and the gas above piston 17, which is at first under highpressure, may escape through the channel 240 to the lowpressure chamber LP within insulator 25. The piston 17 will, therefore, be pressed upwardly in the direction of the two arrows, whereby gas under high pressure streams through the opening 15. Shortly before reaching the end position, the valve head 22 is lifted. There is then high pressure above as well as below the piston 17. In the interim the valve head 24a has returned to the closing position. If the circuit is to be opened, the valve head 23 is lifted through the insulating rod 29 and the space below piston 17 is evacuated, whereupon piston 17 moves downwardly.

FIG. 2 shows a second embodiment of the invention wherein components similar to those of FIG. 1 have been given similar identifying numerals. In FIG. 2, the movable tubular contact 9 is replaced by angularly movable conductive members 41 and 42, which are electrically connected in series and are pivotally mounted on the common pivot 42a. The left-hand lever 41 is driven in a manner similar to that described in FIG. 1, and by means of the piston rod 18, bell crank 19 and link 21. Lever 42 is driven by virtue of the connecting links 43, 44 and 45 where links 43 and 44 are pivotally connected to levers 41 and 42 at their bottoms, while links 43, 44 and 45 are all connected to the same common pivot. The opposite end of link 45 is then pivotally connected by a suitable pin 46 to yoke 47 which is secured to housing 1.

This linkage causes lever 42 to move identically with lever 41 with a counter-rotating action. That is, when lever 41 rotates counterclockwise, lever 42 rotates clockwise through a similar angle.

The stationary contacts at the interior ends of conductors and 6 are then formed as cup-shaped stationary contacts 50 and 51. The ends of contact arms 41 and 42 carry cylindrical nozzles 48 and 49, respectively, which are engageable with stationary contacts 50 and 51, respectively, and slide telescopically within conduits 54 and 55, respectively. Suitable seals 52 and 53 may be provided to insure good sealing engagement between cylindrical contacts 48 and 49 and conduits 54 and 55, respectively. The conduits 54 and 55 are then each connected to the interior of chamber 14a, as schematically illustrated in dotted lines leading to the common inlet opening 15.

The operation of the apparatus of FIG. 2. is essentially identical to that described above for FIG. 1. Thus, when valve 23 is opened, piston 17 moves downward, thereby moving the cylindrical nozzle contacts 4 8 and 49 out of engagement with stationary contacts 50 and 51, with the nozzles 48 and 49 sliding telescopically into conduits 54 and 5-5. The high-pressure gas within chamber 1 will now flow through the nozzles 48 and 49 and into conduits 54 and 55, respectively, to extinguish the arcs drawn to the nozzle contacts 50 and 51, respectively. Reclosing of the apparatus of FIG. 2 is then accomplished by opening valve 24, which may be constructed as shown in FIGS. 1 and 10, thereby evacuating the space above piston 17 to permit the upward movement of piston 17 and thus the counter-rotation of levers 41 and 42 to their engaged positions.

The arrangement of FIG. 2 has the advantage of permitting a straighter line of gas flow from the interior volume of chamber 1, through conduits 54 and 55, into the volume within chamber 14a. Moreover, the arrangement of FIG. 2 avoids the need for a rotating hollow joint, as required in FIG. 1.

Although this invention has been described with respect to its preferred embodiments, it should be understood that many variations and modifications will now be obvious to those skilled in the art, and it is preferred, therefore, that the scope of the invention be limited not by the specific disclosure herein, but only by the appended claims.

The embodiments of the invention in which an exclusive privilege or property is claimed are defined as follows:

1. A high voltage gas blast circuit breaker comprising a high-pressure gas chamber; first and second stationary contacts positioned within said high-pressure gas chamber; insulated terminal means extending through said high-pressure gas chamber and supporting said first and second stationary contacts, respectively, in fixed, spaced relation to one another; angularly movable bridging contact means having first and second end portions angularly movable into and out of engagement with said first and second stationary contacts; pivotal support means within said high-pressure gas chamber positioned between said first andsecond stationary contacts and pivotally supporting said bridging contact means at a central portion thereof; operating means connected to said bridging contact means for angularly moving said bridging contact means around said pivotal support means; a relatively low-pressure gas volume; said first and second end portions of said movable bridging contact means forming first and second gas flow conduits for receiving a gas flow through arcs drawn from said first and second stationary contacts; and a valve; said high-pressure chamber communicating with one end of each of said first and second gas flow conduits; the opposite ends of said gas flow conduits connected together and connected to said low-pressure gas volume through said valve; said valve moving between open and closed positions; valve operating means connecting said valve to said operating means whereby said valve is opened when said movable bridging contact means moves to a disengaged position relative to said first and second stationary contacts; and a cylinder means for supporting said high-pressure chamber; said cylinder means containing a piston therein con nected to said movable bridging contact means and comprising said valve operating means; said first and second gas flow conduits connected to the interior of said cylinder means at a region below said piston; said valve connected to the bottom of said cylinder means whereby opening said valve connects the bottom of said piston and said first and second gas flow conduits to low pressure thereby to move said piston, and to move said movable bridging contact means to a disengaged position, and to discharge gas through said first and second gas flow conduits.

2. The apparatus of claim 1 wherein said movable contact comprises a hollow, rigid conductive tube having nozzle-shaped end portions facing in opposite directions and which respectively engage said first and second stationary contacts.

3. The apparatus of claim 1 wherein said movable contact means comprises first and second counter-rotating contact arms pivotally mounted on said pivotal support means; said first and second end portions of said movable contact means having first and second hollow tubular portions engageable with said first and second stationary contacts; and first and second tube means telescopically receiving portions of said first and second hollow tubular portions, respectively, and defining said first and second gas fiow conduits, respectively.

4. The apparatus of claim 3 wherein said operating means is connected to said first contact arm; and linkage means connected between said first and second contact arms for causing said second contact arm to counterrotate with equal angular displacement with respect to said first contact arm.

References Cited UNITED STATES PATENTS 11/1959 Wood.

6/ 1967 Van Sickle et a1. 

